Windscreen wiper device

ABSTRACT

A windscreen wiper device ( 1 ) comprising an elastic, elongated carrier element, as well as an elongated wiper blade ( 2 ) of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade ( 2 ) includes opposing longitudinal grooves ( 3 ) on its longitudinal sides, in which grooves ( 3 ) spaced-apart longitudinal strips ( 4 ) of the carrier element are disposed, wherein neighbouring ends of said longitudinal strips ( 4 ) are interconnected by a respective connecting piece ( 6 ), which windscreen wiper device ( 1 ) comprises a connecting device ( 7 ) for an oscillating wiper arm ( 8 ), wherein said oscillating arm ( 8 ) is pivotally connected to said connecting device ( 7 ) about a pivot axis near one end, a special feature of which is that said connecting device ( 7 ) comprises engaging members ( 9 ) being welded to longitudinal sides ( 10 ) of said longitudinal strips ( 4 ) that face away from each other in such a manner as to withstand shearing forces in a direction along said longitudinal strips ( 4 ).

The invention relates to a windscreen wiper device comprising anelastic, elongated carrier element, as well as an elongated wiper bladeof a flexible material, which can be placed in abutment with awindscreen to be wiped, which wiper blade includes opposing longitudinalgrooves on its longitudinal sides, in which grooves spaced-apartlongitudinal strips of the carrier element are disposed, whereinneighbouring ends of said longitudinal strips are interconnected by arespective connecting piece, which windscreen wiper device comprises aconnecting device for an oscillating wiper arm, wherein said oscillatingarm is pivotally connected to said connecting device about a pivot axisnear one end.

Such a windscreen wiper device is generally known. The prior artwindscreen wiper device is in particular designed as a “yokeless” wiperdevice, wherein use is no longer made of several yokes pivotallyconnected to each other, but wherein the wiper blade is biassed by thecarrier element, as a result of which it exhibits a specific curvature.The oscillating arm of the prior art windscreen wiper device comprises aprojecting pin on one side thereof, which is inserted sideways into athrough hole of the connecting device.

The connecting device is attached to the unit consisting of the elongatewiper blade and the longitudinal strips through a clamping operation,wherein clamping parts of said connecting device are clamped roundlongitudinal sides of the strips. In order to lock said connectingdevice in a direction along the longitudinal strips, said strips areeach provided with a recess at their exterior longitudinal side so thatthe clamping parts of the connecting device rest in said recess.Obviously, cutting such a precisely shaped recess in each longitudinalstrip needs additional tools and an extra step in manufacturing saidwindshield wiper device.

The object of the invention is to overcome the drawbacks of the priorart as indicated above, in particular to provide a windscreen wiperdevice wherein the connecting device and the unit consisting of thewiper blade and the strips are interconnected in a durable, solidmanner, without the need of additional tools and an extra cutting stepin the manufacturing process of the windshield wiper device.

In order to accomplish that objective, a windscreen wiper device of thekind referred to in the introduction is characterized in that saidconnecting device comprises engaging members being welded tolongitudinal sides of said longitudinal strips that face away from eachother in such a manner as to withstand shearing forces in a directionalong said longitudinal strips. Said engaging members are welded alongtheir entire length to the longitudinal strips or at several pointsalong their length.

In a preferred embodiment of a windscreen wiper device according to theinvention the engaging members are welded to said longitudinal sidesthrough an ultrasonic welding operation. To this end, the connectingdevice and the engaging members are preferably made in one piece ofthermoplastic material (whether or not enforced by glass fibers),wherein said longitudinal strips are either entirely made ofthermoplastic material as well or provided with a thermoplastic skin. Inthe latter case the longitudinal strips can be made by co-extrusion of athermoplastic around a steel wire.

In another preferred embodiment of a windscreen wiper device accordingto the invention the end of the oscillating wiper arm includes two atleast substantially cylindrical protrusions, which form bearingsurfaces, at the location of the pivot axis, which protrusions extend inlateral direction with respect to the oscillating wiper arm. In anotherpreferred embodiment the end of the oscillating wiper arm has an atleast substantially U-shaped cross-section, said connecting device beingpartially positioned within said end of the oscillating arm, wherein theend of the oscillating arm is provided, at the location of the pivotaxis, with a shaft extending between the legs of the U-shapedcross-section, said shaft pivotally engaging in said connecting device.As a result, the two protrusions/shaft that function(s) as bearingsurface(s) is/are spaced far apart, so that the forces that are exertedon said bearing surface(s) will be relatively low. In particular, theprotrusions/shaft can be pivotally fitted in correspondingly shapedrecess(es) in the connecting device.

In another preferred embodiment of a windscreen wiper device accordingto the invention, the protrusions/shaft can be snapped into saidrecess(es).

In another preferred embodiment of a windscreen wiper device accordingto the invention, the protrusions/shaft are/is dimensioned such thatthey/it can be passed through (an) insertion opening(s) of therecess(es) from an at least substantially perpendicular position of theoscillating arm with respect to the wiper blade, and be locked inposition in said recess(es) from an at least substantially parallelposition of the oscillating wiper arm with respect to the wiper blade.This makes it possible to move, in particular pivot, the oscillatingwiper arm from a mounting position (that is, a (vertical) positionperpendicularly to the wiper blade or the plane of a windscreen to bewiped) to an operative position (that is, a (horizontal) positionparallel to the wiper blade or the plane of a windscreen to be wiped).In the mounting position, the protrusions/shaft can be freely insertedinto the insertion opening(s) of the recess(es) and subsequently bemounted in said recess(es), whilst in the operative position theprotrusions/shaft are/is locked in position in said recess(es), so thatthey/it cannot move out of said recess(es) via the insertion opening(s).

In another preferred embodiment of a windscreen wiper device accordingto the invention, the connecting device includes a guide groove for theoscillating wiper arm. Since the oscillating wiper arm is at leastpartially disposed in said guide groove in the aforesaid operativeposition, the oscillating wiper arm comprises additional capability ofwithstanding relatively high torques in that position.

In another preferred embodiment of a windscreen wiper device accordingto the invention, said connecting pieces are clamping members, whichform separate constructional elements. In particular, said connectingpieces are form-locked (“positive locking” or “having positive fit”) orforce-locked to the adjacent ends of the longitudinal strips.

In another preferred embodiment of a windscreen wiper device accordingto the invention, said connecting pieces are in one piece with saidlongitudinal strips.

In another preferred embodiment of a windscreen wiper device accordingto the invention, at least said longitudinal strips are made of springband material, preferably steel, coated with a thermoplastic material.

The invention furthermore relates to a method for manufacturing awindscreen wiper device according to the invention, wherein opposinglongitudinal grooves are formed in the longitudinal sides of anelongated wiper blade of a flexible material, which can be placed inabutment with a windscreen to be wiped, in which grooves longitudinalstrips of a carrier element are subsequently fitted in spaced-apartrelationship, wherein neighbouring ends of said longitudinal strips areinterconnected by a respective connecting piece, wherein an oscillatingarm is pivotally connected to a connecting device of the windscreenwiper device about a pivot axis near one end thereof, characterized inthat said connecting device is fitted with engaging members, which arewelded to longitudinal sides of said longitudinal strips that face awayfrom each other in such a manner as to withstand shearing forces in adirection along said longitudinal strips.

The invention will now be explained in more detail with reference tofigures illustrated in a drawing, wherein:

FIG. 1 is a perspective, schematic view of a preferred embodiment of awindscreen wiper device according to the invention;

FIGS. 2 and 3 show details of the windscreen wiper device of FIG. 1,wherein various successive steps for fitting an oscillating wiper arm toa connecting device of the windscreen wiper device of FIG. 1;

FIGS. 4, 5 and 6 correspond to FIGS. 1, 2 and 3, respectively, butrelating to another preferred embodiment;

FIG. 7 corresponds to FIG. 5, but relating to a further preferredembodiment; and

FIGS. 8 and 9 refer to a cross-sectional view of the connecting deviceof the windscreen wiper device of FIG. 1, before and after a preferredadditional retention operation to hold said connection device intoposition, respectively.

FIGS. 1, 2 and 3 show a preferred variant of a windscreen wiper device 1according to the invention. Said windscreen wiper device is built up ofan elastomeric wiper blade 2, in the longitudinal sides of whichopposing longitudinal grooves 3 are formed, and of longitudinal strips 4made of spring band steel, which are fitted in said longitudinal grooves3. Said strips 4 form a flexible carrier element for the rubber wiperblade 2, as it were, which is thus biassed in a curved position (thecurvature in operative position being that of a windscreen to be wiped).Neighbouring ends 5 of strips 4 are interconnected on either side of thewindscreen wiper device 1 by means of connecting pieces 6 functioning asclamping members. In this embodiment, the connecting pieces 6 areseparate constructional elements, which may be form-locked (“positivelocking” or “having positive fit”) as well as force-locked to the ends 5of strips 4. In another preferred variant, said connecting pieces 6 arein one piece with the strips 4 made of spring band steel. In the lattercase said connecting pieces form transverse bridges for the strips 4, asit were.

The windscreen wiper device 1 is furthermore built up of a connectingdevice 7 of plastic material for an oscillating wiper arm 8. Connectingdevice 7 comprises engaging members 9 that are integral therewith, whichare welded to longitudinal sides 10 of the strips 4 that face away fromeach other, as a result of which the connecting device 7 is firmlyattached to the unit consisting of wiper blade 2 and strips 4. In thisrespect it is noted that the connecting device 7 is made of athermoplastic material and the strips 4 are made of steel with athermoplastic skin (coating). The engaging members 9 engage around saidstrips 4 or—in other words—said strips 4 are mounted in grooves formedby the engaging members 9. The oscillating wiper arm 8 is pivotallyconnected to the connecting device 7 about a pivot axis near one end,and that in the following manner. The end of oscillating wiper arm 8includes two at least substantially cylindrical protrusions 11, whichform bearing surfaces, at the location of the pivot axis. Saidprotrusions 11 can be readily inserted into correspondingly shapedrecesses 12 in the connecting device 7 from a vertical position of theoscillating wiper arm 8. This can take place freely from said verticalposition, because the width of said protrusions 11 is smaller than thatof the insertion openings 13 of the recesses 12 in that position: it sohappens that both protrusions 11 have a flat guide surface 14 (FIG. 2).Then the oscillating wiper arm 8 is pivoted through 90 degrees about thepivot axis, from its vertical position to a horizontal position (FIG.3). In the horizontal position of the oscillating wiper arm 8, the widthof said protrusions 11 is smaller than the width of the insertionopenings 13 of recesses 12, so that the oscillating wiper arm 8 islocked with respect to the connecting device 7 in that position (FIG.3). FIGS. 2 and 3 clearly show that the connecting device 7 includes alongitudinal guide groove or guide slot 15, in which the end of theoscillating wiper arm 8 rests in its horizontal position. In anotherpreferred variant, the protrusions 11 can be snapped, that is, clippedinto said recesses. Possibly, a spoiler 16 is furthermore provided.

As already mentioned above, FIGS. 4, 5 and 6 correspond to FIGS. 1, 2and 3, respectively, but relating to another preferred embodiment,wherein corresponding parts are designated with the same referencenumerals.

The end of oscillating wiper arm 8 has an at least substantiallyU-shaped cross-section at the location of its connection to theconnecting device 7. On both sides of the legs of the U-shapedcross-section the end of oscillating wiper arm 8 includes two at leastsubstantially cylindrical, inwardly extending protrusions 11, which formcylindrical bearing surfaces, at the location of the pivot axis. Saidprotrusions 11 can also be readily inserted into a correspondinglyshaped recess 12 in the connecting device 7 from a vertical position ofthe oscillating wiper arm 8. This again can take place freely from saidvertical position, because also in this case the width of saidprotrusions 11 is smaller than that of the insertion opening 13 of therecess 12 in that position: both protrusions 11 have a flat guidesurface 14 (FIG. 5). Then the oscillating wiper arm 8 is pivoted through90 degrees about the pivot axis, from its vertical position to ahorizontal position (FIG. 6). In the horizontal position of theoscillating wiper arm 8, the width of said protrusions 11 is larger thanthe width of the insertion opening 13 of the recess 12, so that theoscillating wiper arm 8 is locked with respect to the connecting device7 in that position (FIG. 6). In another preferred variant, theprotrusions 11 can be snapped, that is, clipped into said recess 12.Instead of one recess 12 as shown, also two recesses (one for eachprotrusion 11) may be used.

FIG. 7 corresponds with FIG. 5, wherein parts corresponding with partsof FIG. 5 are designated with the same reference numerals. Instead oftwo protrusions 11 extending between both legs of the U-shapedcross-section 1, now use is made of a pin 17 extending from one leg tothe other leg of the U-shaped cross-section. The way of connecting theoscillating arm 8 to the connecting device 7 is identical to the waydescribed in relation to FIGS. 5 and 6.

In order to prevent the occurrence of wear on protrusions 11 or pin 17,said protrusions or pin are preferably each fitted with a joint part orspacer of a wear-resistant plastic material, which surrounds saidprotrusions or pin, so that the pivoting movement of connecting device 7and oscillating wiper arm 8 with respect to each other takes placesubstantially without friction. Such a joint part is not necessarilymounted entirely around said protrusions or pin: only these parts ofsaid protrusions or said pin that during use make mechanical contactwith (parts of) the connecting device 7 are surrounded by a joint part.When using joint parts said protrusions 11 or said pin may have anentirely round form (i.e. without a guide surface), seen incross-section. Preferably, the end of the oscillating arm 8 that restsin the guide groove 15 shown in FIG. 2 is also surrounded by a jointpart or spacer of a wear-resistant plactic material.

In a preferred embodiment the connecting device 7 is firmly retainedonto the wiper blade 2 through a retention operation comprising thefollowing steps: a warm stamp 18 is moved downwardly, thus ensuring an(ultrasonic) deformation of the plastic material of the connectingdevice 7 onto the elastomeric material of the wiper blade 2. In otherwords, the head 19 of the elastomeric wiper blade 2 is “squeezed”between plastically deformed material of the connecting device 7. FIG. 8refers to a situation before the welding step of the warm stamp 18,whereas FIG. 19 relates to a situation (ultrasonically) after thatwelding step.

In another preferred embodiment the connecting pieces 6 designed asseparate constructional elements being made of a thermoplastic materialare welded to the longitudinal sides 10 of the strips 4 being made ofsteel with a thermoplastic skin (coating). The invention is notrestricted to the variants as shown in the drawing, but it also extendsto other embodiments that fall within the scope of the appended claims.

1. A windscreen wiper device (1) comprising an elastic, elongated carrier element, as well as an elongated wiper blade (2) of a flexible material, which can be placed in abutment with a windscreen to be wiped, which wiper blade (2) includes opposing longitudinal grooves (3) on its longitudinal sides, in which grooves spaced-element are disposed, wherein neighbouring ends of said longitudinal strips (4) are interconnected by a respective connecting piece (6), which windscreen wiper device (1) comprises a connecting device (7) for an oscillating wiper arm (8), wherein said oscillating arm is pivotally connected to said connecting device (7) about a pivot axis near one end, characterized in that said connecting device (7) comprises engaging members (9) being welded to longitudinal sides (10) of said longitudinal strips (4) that face away from each other in such a manner as to withstand shearing forces in a direction along said longitudinal strips (4).
 2. A windscreen wiper device according to claim 1, wherein said engaging members (9) are welded to said longitudinal sides (10) through an ultrasonic welding operation.
 3. A windscreen wiper device according to claim 1, wherein said connecting device (7) and said engaging members (9) are made in one piece.
 4. A windscreen wiper device according to claim 1, wherein the end of the oscillating wiper arm (8) includes two at least substantially cylindrical protrusions (11), which form bearing surfaces, at the location of the pivot pin, which protrusions extend in lateral direction with respect to the oscillating wiper arm (8).
 5. A windscreen wiper device according to claim 1, wherein the end of the oscillating wiper arm (8) has an at least substantially U-shaped cross-section, said connecting device (7) being partially positioned within said end of the oscillating arm (8), and wherein the end of the oscillating arm (8) is provided, at the location of the pivot axis, with a shaft extending between the legs of the U-shaped cross-section, said shaft pivotally engaging in said connecting device (7).
 6. A windscreen wiper device according to claim 4, wherein said protrusions (11)/said shaft can be pivotally mounted in (a) correspondingly shaped recess(es) (12) in the connecting device (7).
 7. A windscreen wiper device according to claim 6, wherein said protrusions (11)/said shaft can be snapped into said recess(es) (12).
 8. A windscreen wiper device according to claim 6, wherein said protrusions (11)/said shaft are/is dimensioned such that they/it can be passed through (an) insertion opening(s) (13) of the recess(es) (12) from an at least substantially perpendicular position of the oscillating arm (8) with respect to the wiper blade (2), and be locked in position in said recess(es) (12) from an at least substantially parallel position of the oscillating wiper arm (8) with respect to the wiper blade (2).
 9. A windscreen wiper device according to claim 1, wherein said connecting pieces (6) are clamping members, which form separate constructional elements.
 10. A windscreen wiper device according to claim 9, wherein said connecting pieces (6) are form-locked or force-locked to the adjacent ends of said longitudinal strips (4).
 11. A windscreen wiper device according to claim 1, wherein said connecting pieces (6) are in one piece with said longitudinal strips (4).
 12. A windscreen wiper device according to claim 1, wherein at least said longitudinal strips (4) are made of spring band material.
 13. A method for manufacturing a windscreen wiper device, wherein opposing longitudinal grooves (3) are formed in the longitudinal sides of the elongated wiper blade (2) of a flexible material, which can be placed in abutment with a windscreen to be wiped, in which grooves longitudinal strips (4) of a carrier element are subsequently fitted in spaced-apart relationship, wherein neighbouring ends of said longitudinal strips (4) are interconnected by a respective connecting piece (6), wherein an oscillating arm (8) is pivotally connected to a connecting device (7) of the windscreen wiper device (1) about a pivot axis near one end thereof, characterized in that said connecting device (7) is fitted with engaging members (9), which are welded to longitudinal sides (10) of said longitudinal strips (4) that face away from each other in such a manner as to withstand shearing forces in a direction along said longitudinal strips (4). 